1. Field
One embodiment of the present invention relates to a head used in a disk device such as a magnetic disk device, a head suspension assembly provided with the head, and a disk device provided with the head suspension assembly.
2. Description of the Related Art
A disk device, e.g., a magnetic disk device, includes a magnetic disk, spindle motor, magnetic head, and carriage assembly. The magnetic disk is arranged in a case. The spindle motor supports and rotates the disk. The magnetic head writes and reads information to and from the disk. The carriage assembly supports the head for movement with respect to the disk. The carriage assembly includes a rockably supported arm and a suspension extending from the arm. The magnetic head is supported on an extended end of the suspension. The head includes a slider attached to the suspension and a head portion on the slider. The head portion is constructed including a reproducing element for reading and a recording element for writing.
As modern magnetic disk devices have become smaller and smaller, their application to mobile equipment has spread more widely. The magnetic disk devices for mobile application require operation shock resistance and high height security. The slider has a facing surface (air bearing surface (ABS)) that is opposed to a recording surface of the magnetic disk. A predetermined head load directed to a magnetic recording layer of the disk is applied to the slider by the suspension.
When the magnetic disk device operates, air-flows are produced between the disk in rotation and the slider. Based on the principle of aerodynamic lubrication, a force (positive pressure) to fly the slider above the recording surface of the disk acts on the facing surface of the slider. By deliberately shaping the facing surface of the slider to balance this flying force with the head load, the slider can be flown stably with an infinitesimal gap of about 10 nm above the recording surface of the disk without contacting the disk surface. Thus, high-density recording, high-speed data access, and high reliability are achieved by the magnetic head.
The design of the facing surface of the slider is essential to the attainment of the operation shock resistance and height security of the magnetic head described above. The “height security” implies prevention of a reduction in the flying height of the slider under a reduced-pressure environment, and it will hereinafter be referred to as reduced-pressure performance. In order to improve the operation shock resistance and the reduced-pressure performance, it is important to make the slider hard to be separated from the disk surface when jolted and to prevent the flying height from being reduced during decompression.
As described in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-123422, there is a known disk device in which a negative-pressure cavity or a dynamic-pressure producing groove is formed near the center of a facing surface of a slider in order to prevent variation of the flying height of the slider. Specifically, the slider includes a negative-pressure groove formed at the central part of an ABS, a leading step provided on the inflow-end side of the slider, and a trailing step on the outflow-end side of the slider, and a magnetic head is provided on the trailing step.
The leading step is provided with a leading pad for use as a pressure producing pad. The leading pad is formed narrow so that the negative-pressure cavity is as large as possible on the inflow side of the slider. In order to increase a pressure produced by the leading pad, moreover, step portions of different depths are formed on the inflow side of the leading pad. Gaps between the disk surface and the step portions gradually narrow toward the leading pad.
Although the operation shock resistance and the reduced-pressure performance can be improved by deliberately shaping the facing surface of the slider in the aforesaid manner, a higher pressure should preferably be produced by trapping more air. If the slider is skewed, moreover, the pressure that is produced by the leading pad to act on air-flows cannot be enhanced.